In an optical system of the field of stage lighting, due to various influencing factors, formed light spots projected by stage lighting are often found in problems of non-uniform luminance (overall non-uniform), black spots (locally non-uniform) and so forth when stage lighting is used for projecting light beam toward a stage or other target regions. To solve the above problems, in the prior art, as shown in FIG. 1, an optical integrator 2, such as a light-guiding pipe or a light-guiding rod, a microlens array, or an atomization piece, is generally disposed between a light source assembly 1 and an object assembly 3 to obtain relatively uniform light spots. Wherein, a concentrated beam is emitted by said light source assembly 1, becomes uniform via the optical integrator assembly 2, and then is shot after entering into the object assembly 3.
In normal conditions, however, if only the optical integrator is used, such as a light-guiding pipe or a light-guiding rod, the required length is relatively long, since the uniformity problems of the light spots eventually projected by the light-guiding pipe or light-guiding rod are closely bound up with the size of the light-guiding rod.
Usually, in order to achieve desired effects, the length of the light-guiding pipe or light-guiding rod will be relatively long. In this case, when designing stage lighting, the size of the optical integrator (e.g. light-guiding pipe or light-guiding rod and so forth) needs to be designed fairly long if a better uniformity of light spots is required. The optical integrator occupies more space, causing that both other light source modules and the optical integrator (e.g. light-guiding pipe or light-guiding rod and so forth) need to be designed to avoid the optical integrator, such that it fails to obtain the ideal design. Moreover, as shown in FIG. 2, the light beam processed with the existing optical integrator still shines according to certain rule and direction, without realizing complete scattering, and there often will be a locally non-uniform phenomenon in the formed light spots.